Vacuum pump

ABSTRACT

A vacuum pump comprising a closed housing, an elastometric diaphragm in the form of a cup therein, said diaphragm having a rim, said rim being sealed into the wall of the housing, said diaphragm dividing the housing into two chambers one including the interior of the diaphragm and the other being at the exterior thereof, a constant vacuum outlet for the latter chamber and a pair of check valves which are substantially the same but reversed for the chamber at the interior of the diaphragm.

0 United States Patent [151 amasmm Grise 1 Jan. 18, W72

[54] VACUUM PUMP 1,627,257 5/1927 Stevens ..417/395 [72] Inventor:Frederick J. arise, North Brookfield 2,738,731 3/1956 Browne ..417/394SS Primary Examiner-Robert M. Walker [73] Assignee: Novelty Tool Co.,Inc., Spencer, Mass. ch R F [22] Filed: Apr. 20, 1970 ABSTRACT [21]Appl. No.: 29,989 I A vacuum pump comprising a closed housing, anelastometric diaphragm in the form of a cup therein, said diaphragmhaving [52] 11.5. CI ..4l7/394 a rim Said rim being sealed into the n ofthe housing, Said [5 1 1 Cl "Fo4b 43/10 F04b 45/00 diaphragm dividingthe housing into two chambers one includ- [58] Field of Search..417/394, 395 ing the interior ofthe diaphragm and the other being atthe 5 6] R t d terior thereof, a constant vacuum outlet for the latterchamber e erences I e and a pair of check valves which are substantiallythe same but UNITED STATES PATENTS reversed for the chamber at theinterior of the diaphragm. 1,268,780 6/1918 Jay ..417/395 3 Claims, 41Drawing Figures PATENTEB m 1 a 1972 I Z r]! M 50 Z j Z0 8 JV 50 20 47-52 46 I 7 z! 32 26 J W 4 J6 2% 4 jg 5a z? J6 F 3 5 & 0 50 6 5 52 9-115 KM 50 J? 46 20 if 32 4-30 M50 i 32 42 44 74 a I I 32 26 34 36 I y 7635 L'J z I k 32 Z4 f rarcia rick 626 7332 r 34 I? as 36 737 W? vAcuuMPUMP BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION A housing isprovided, said housing being generally cylindrical and having at one enda connection for a vacuum line and at its opposite end two connections,each of the latter being provided with a check valve one of which allowsintake of fluid into the housing, the other allowing fluid to be ejectedfrom the housing under pressure. There is a cup-shaped elastometricdiaphragm having a bottom extending in relatively close association withrespect to the vacuum line connection and at its open end having a rimwhich is substantially permanently sealed into the wall of the housingadjacent the two check valves. There is a notched rim surrounding thevacuum line connection within the housing facing a projecting continuousseal on the exterior of the bottom of the cuplike elastometricdiaphragm. The diaphragm divides the housing into two chambers, one atthe exterior of the cup-shaped diaphragm and the other at the interiorthereof, the vacuum connection being for the exterior chamber and thecheck valves being in the interior chamber.

There is also a small bleed hole to the atmosphere in the housing forallowing the atmosphere to enter into the housing between the exteriorsurface of said cuplike diaphragm and the vacuum line connection, i.e.,into the exterior chamber.

The vacuum may be constant and gradually causes the diaphragm to stretchand the bottom of the diaphragm to approach the vacuum connection. Whenthe bottom of the cuplike diaphragm reaches the notched rim circumjacentto the vacuum connection, the latter partially cuts off the vacuumconnection from the exterior chamber of the housing, between the cuplikediaphragm and the inside wall of the housing. Of course atmosphericpressure has been constantly leaking into the exterior chamber in thehousing through the bleed hole, but as yet the pressure does not equalthe degree of vacuum. The bottom of the diaphragm is thus stopped, andthe effect is that the sidewall of the diaphragm bulges until itcontacts the wall of the housing about the notched rim. The bulging ofthe diaphragm increases the intake of fluid into the interior chamberthrough the intake check valve until the contact just described, whichcauses a definite, instant cut off of the vacuum from the housing. Thepressure increases very suddenly and this has the effect of collapsingthe diaphragm to its normal position, thus forcing the fluid out of theexit check valve in a spurt and under considerable pressure. The actionthen repeats and does so as long as the vacuum is in effect.

This action is completely continuous and the size of the bleed hole tothe atmosphere and the degree of vacuum determines the actual cycling ofoperation of the valve and the degree of pressure with which the fluidspurts out.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a view in elevationillustrating the valve;

FIG. 2 is a section illustrating the valve in normal condition of thediaphragm;

FIG. 3 is a similar view illustrating the action of the diaphragm, and

FIG. 4 shows the diaphragm in its maximum stretched condition.

PREFERRED EMBODIMENT OF THE INVENTION A main-housing part generallyindicated at 10 has a closed end 12 and in the case illustrated an openend at I4. In the closed end there is a central connection 16 forattachment to a vacuum line and surrounding this connection at theinside of the end 12 there is an annular projecting rim 113 having aseries of notches 20 therein. This part of the housing is convenientlymolded of clear plastic so that the action, to be described, is clearlyvisible.

A housing part generally indicated at. 22 is provided with a rim 24corresponding to rim 26 at the open end M of the housing part for thepurpose of substantially permanently sealing therein the outstanding rim2% of an elastometric cupshaped diaphragm generally indicated at 30. Therim 2% is provided with extension ridges 32, 32 which fit intocorresponding recesses in the rims 24 and 26 for the purpose of solidlygripping the rim 28 so that it cannot creep out under any circumstances.The diaphragm divides the housing into two chambers, one exterior of thediaphragm and the other exterior thereof.

The housing part 22 is provided with two annular valve holding portions34 and 36, each of which is provided with a connection for a tube as at38 and 40. Each of the annular portions 34 and 36 is provided with acheck valve of conventional design, these being indicated at 42, 441.One check valve allows only pressure inwardly through its connectioninto the in terior of the cuplike diaphragm 3t) and the other checkvalve allows only ejection of fluid material from the cuplike diaphragm30.

The cuplike diaphragm 30 has an upstanding wall 416 and a closed endportion 48 at the exterior of which there is an upstanding continuousring 50.

With the parts as shown in FIG. 2 and assuming a vacuum line connectedat 16, the exterior chamber between the housing I0 and the elastometricdiaphragm 30 will begin to be exhausted even though a slight amount ofatmospheric air leaks in through a small hole 52. The bottom 48 ofdiaphragm 30 is pulled upwardly toward the source of vacuum, thediaphragm stretching, see for instance FIG. 3, and eventually theexterior surface of the diaphragm bottom as contacts the rim 1b. Whenthis happens, it is more difficult for the vacuum to extract air as thisair can only pass through notches 20 inwardly from the interior ofhousing 10 to the connection 16. Nevertheless the vacuum still acts onthe diaphragm and since the center portion of the bottom 48 thereofcannot proceed any further upwardly, the elastometric wall 46 bulges,see FIG. 4, until the ring 50 contacts the inside surface of the bottom12 0f the housing part It). At this instant, the diaphragm issubstantially full of fluid.

At this instant, all of the vacuum action is cut off from the exteriorchamber, i.e., between the interior wall of housing part It) and thebulged out exterior wall 46 of diaphragm 30, so that the atmosphericleak through the hole 52 sharply causes a relatively high pressurebetween the housing and the diaphragm which causes the latter toactually snap from the FIG. 4 position back to the original FIG. .2position.

When this snap off occurs, the wall of "the diaphragm as well as thebottom thereof quickly snap inwardly from FIG. 4 to FIG. 2 position, andsince check valve 33 will not allow any return, some fluid in thediaphragm is expelled in a spurt or jet through the valve 414 andconnection 40.

It will therefore be seen that a pulsating action is provided forsupplying fluid in seriatim jets and this action will last as long asthere is a reservoir of fluid connected to connection 38 and a vacuum toconnection I6. The sealing arrangement of the rims 24 and 26 togetherwith rim 28 prevents any dislodgment of the parts and the only movingparts are the diaphragm itself and the check valves at 412 and Ml.

Increased vacuum will cause a faster action, and varying the size ofhole 52 will also affect the action, but otherwise it will be seen thatan extremely simple pulsating fluid pump is provided and this pump willoperate as long as the vacuum is applied and the fluid reservoir is inoperation.

Iclaim:

I. A vacuum pump comprising a housing, a connection for admitting vacuumto said housing in one area thereof and a pair of check valves in adifferent area thereof, said check valves operating independently andoppositely to each other,

an elastometric diaphragm in said housing, said diaphragm said housingincluding a sidewall greater in diameter then the diameter of the cup,providing an annular space between the walls, said space being at leasta part of the first chamber,

vacuum from the vacuum connection acting upon said diaphragm to causethe same to stretch toward it and the cup walls to expand toward thehousing wall reducing the volume of the first chamber and therebycausing fluid material to enter into the second chamber, the bottom ofthe cup being constructed and arranged to substantially cutoff thevacuum relative to said first chamber to provide that the pressureentering from the atmosphere overcomes the vacuum action and causes thediaphragm to snap back from its stretched condition expelling fluid in ajet through one of the check valves.

2. The vacuum pump of claim 1 including means initially partiallyshutting off the vacuum and causing the bottom of the diaphragm cup tobend into contact with the housing about the vacuum connection andwholly shutting off the vacuum substantially simultaneously with theexpansion of the sidewall of the cup.

3. The vacuum pump of claim 1 including a rim about the vacuumconnection at the interior of the housing, the bottom of the cup comingin contact with the rim and stopping further elongation of the cup at acertain point in the stretch of the cup.

1. A vacuum pump comprising a housing, a connection for admitting vacuumto said housing in one area thereof and a pair of check valves in adifferent area thereof, said check valves operating independently andoppositely to each other, an elastometric diaphragm in said housing,said diaphragm being in the form of a cup having a rim, a continuoussidewall, and a closed bottom, means securing the rim of said diaphragmto said housing continuously, dividing the same into a pair of chambers,a first chamber outside the cup including the vacuum connection and asecond and separate chamber inside the cup including the check valves, asmall hole to the atmosphere in a wall of said housing into the firstchamber, said housing including a sidewall greater in diameter then thediameter of the cup, providing an annular space between the walls, saidspace being at least a part of the first chamber, vacuum from the vacuumconnection acting upon said diaphragm to cause the same to stretchtoward it and the cup walls to expand toward the housing wall reducingthe volume of the first chamber and thereby causing fluid material toenter into the second chamber, the bottom of the cup being constructedand arranged to substantially cutoff the vacuum relative to said firstchamber to provide that the pressure entering from the atmosphereovercomes the vacuum action and causes the diaphragm to snap back fromits stretched condition expelling fluid in a jet through one of thecheck valves.
 2. The vacuum pump of claim 1 including means initiallypartially shutting off the vacuum and causing the bottom of thediaphragm cup to bend into contact with the housing about the vacuumconnection and wholly shutting off the vacuum substantiallysimultaneously with the expansion of the sidewall of the cup.
 3. Thevacuum pump of claim 1 including a rim about the vacuum connection atthe interior of the housing, the bottom of the cup coming in contactwith the rim and stopping further elongation of the cup at a certainpoint in the stretch of the cup.